SCIENCE

Flying, fearsome Asian carp have already taken over much of the Mississippi. Can electrical barriers keep them out of the Great Lakes--or do we need to block the waterways to keep the fish from spreading?

BRIEFING

After a confusing flurry of summer primaries leading up to November's midterms, the Aug. 10 Senate contests in Colorado provided some clarity about the mood of the electorate and the parties' prospects for the fall